Tangential and radial shrinkage variation within trees in sugi (Cryptomeria japonica) cultivars

Yamashita, Kana; Hirakawa, Yasuhiko; Nakatani, Hiroshi; Ikeda, Motoyoshi

doi:10.1007/s10086-008-1012-2

Cited by 25 publications

(19 citation statements)

References 20 publications

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“…Depending on the end use, properties considered important for characterizing wood quality may vary, yet basic density is considered the main indicator of wood quality, as it correlates with all other wood properties, including retractability (WU et al, 2006;YAMASHITA et al, 2009), mechanical properties (NASCIMENTO et al, 1997 and anatomy . Also, density affects all processes in which wood is present, including pulping (QUEIROZ et al, 2004), charring (KHRISTOVA; KHALIFA, 1993), machining (Silva et al, 2007), log breakdown etc.…”

Section: Couto a M Et Almentioning

confidence: 99%

Modeling of basic density of wood from Eucalyptus grandis and Eucalyptus urophylla using nondestructive methods

Couto¹,

Trugilho

Neves³

et al. 2013

CERNE

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ABSTRACT:The objective of this study was to evaluate the accuracy of nondestructive variables in inferring basic density of wood from Eucalyptus grandis and Eucalyptus urophylla. A total of 27 clones of Eucalyptus urophylla and 22 clones of Eucalyptus grandis were used, sourced from a clonal trial set up in Martinho Campos, Minas Gerais. After evaluation using nondestructive techniques of resistography and pin penetration at a constant pressure (Pilodyn ® ), individuals were felled and disks were removed from the 2%, 10%, 30%, 50% and 70% portions of the merchantable height section, and also from the portion 1.30 m above ground level. Basic density was determined by the water immersion method. Values of basic density ranged from 0.412 to 0.609 g.cm -3 for clones at age 42 months and from 0.408 to 0.664 g.cm -3 for clones at age 54 months. The clones of Eucalyptus urophylla provided higher values of average basic density in relation to Eucalyptus grandis. The variable 'amplitude' had better correlation with basic density in comparison with pin penetration at a constant pressure. Nondestructive evaluation can be used in mass preselection of genetic materials, prior to subjecting them to a more accurate, reliable evaluation.

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Section: Couto a M Et Almentioning

confidence: 99%

Modeling of basic density of wood from Eucalyptus grandis and Eucalyptus urophylla using nondestructive methods

Couto¹,

Trugilho

Neves³

et al. 2013

CERNE

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“…The sample trees were used in our previous studies on shrinkage [6,7] and bow [8]. The trees of each cultivar were taken from the same stands (boka-sugi: Takaoka, Toyama; aya-sugi and yabukururi: Kahoku, Kumamoto; ryuunohige and kumotooshi: Kikuchi, Kumamoto).…”

Section: Methodsmentioning

confidence: 99%

“…The moisture content of heartwood varies largely among cultivars and along the stem [4,5]. The shrinkage, which is affected by microfibril angle (MFA), density, and tree ring parameters, also exhibits variation among cultivars and within the stem especially at the core of stem [6,7].…”

Section: Introductionmentioning

confidence: 99%

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Surface-check variation in boxed-heart square timber of sugi (Cryptomeria japonica) cultivars dried by the conventional kiln drying

et al. 2012

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To investigate the factors affecting the surfacecheck variation in boxed-heart square timber of sugi (Cryptomeria japonica), surface checks formed by the conventional kiln drying were compared for two stem heights of five cultivars with different wood properties. The total length and average length of the surface checks were greater at the upper part of the stems for all the cultivars. This might be caused by more sapwood at the upper part of the stem, and large drying stresses between the outer sapwood and the inner heartwood. The cultivars, in which tangential shrinkage was large owing to small microfibril angle, formed longer surface checks and smaller bow. There was a positive relationship between surface-check length and tangential shrinkage. The heartwood percentage and tangential shrinkage were thought to be important factors affecting the surface-check variation in sugi boxedheart square timber.

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“…First, transverse anisotropy is prominent in cross-sections, such as different shrinkage coefficients for the tangential and radial direction. Second, due to the material inhomogeneity, wood disks contain different types of wood, i.e., juvenile wood and mature wood as well as heartwood and sapwood (Yamashita et al 2009). Such variations make it difficult to prevent drying defects in wood disks during drying.…”

Section: Introductionmentioning

confidence: 99%

Stress characteristics and stress reversal mechanism of white birch (Betula platyphylla) disks under different drying conditions

Zhao

et al. 2016

Maderas, Cienc. tecnol.

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Drying stress is the main cause for the generation of drying cracks in wood disks during drying, which limits the processing and utilization of this valuable material. For this study, white birch disks with one trunk and a thickness of 30 mm were dried under three different drying conditions: 1) a very slow drying process preventing the generation of a radial moisture content (MC) gradient, 2) a drying process with slowly increasing temperature leading to a radial MC gradient, with a higher MC in the heartwood, and 3) the same heat drying process but the wood disks were partly covered with a thin plastic film prior to the drying process leading to a reversed radial MC gradient, i.e., a higher MC in the sapwood. For each drying condition, the tangential elastic strain in the wood disks was investigated for a mean MC of 26%, 18% and 10%, respectively, as a function of the radial distance from the pith in order to predict the drying stress. Furthermore, the stress characteristics and stress reversal mechanisms in wood disks are discussed in this paper with the help of stress analysis sketches.

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Tangential and radial shrinkage variation within trees in sugi (Cryptomeria japonica) cultivars

Cited by 25 publications

References 20 publications

Modeling of basic density of wood from Eucalyptus grandis and Eucalyptus urophylla using nondestructive methods

Modeling of basic density of wood from Eucalyptus grandis and Eucalyptus urophylla using nondestructive methods

Surface-check variation in boxed-heart square timber of sugi (Cryptomeria japonica) cultivars dried by the conventional kiln drying

Stress characteristics and stress reversal mechanism of white birch (Betula platyphylla) disks under different drying conditions

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